1. Technical Field
The present invention is directed to network systems and, more particularly, to a system for configuring switches in a network.
2. Related Art
Various standards have been developed for network developments. One such standard is known as RapidIO. RapidIO is an open-standard, switched fabric that has substantial use in embedded computing environments. Embedded computing systems using RapidIO technology include wireless infrastructures, edge networking systems, storage systems, as well as scientific, military and industrial equipment.
RapidIO networks include a number of processing elements (PEs) that are interconnected by point-to-point links. The PEs may include switch devices and endpoint devices. In a typical RapidIO network topology, the endpoint devices are interconnected with one another through a fabric formed by the switch devices. Endpoint devices communicate with one another using data packets that, among other things, include an identification of the source and destination endpoint devices. The switch devices of the network use the destination data to route the data packet to the proper endpoint device. In a RapidIO system, each switch device of the network includes at least one routing table that is used to control the I/O fabric of the switch so that it relays a received data packet to the proper output port based on the destination endpoint.
On start up, the RapidIO network executes a process to identify and initialize the various components that constitute the network. During the enumeration process, the routing tables of the switches are established. To this end, at least one PE on the network is designated as an enumerating endpoint. The enumerating endpoint queries for the presence of other PEs on the network. When the enumerating endpoint detects a switch on the network, it records the total number of ports on the switch and the port number through which it reached the switch. The remaining ports of the detected switch may then be checked to determine whether other PEs are attached to these remaining ports. If a PE is detected, the enumerating endpoint queries the detected PE to determine whether it is an endpoint device or a switch device.
The next series of steps executed by the enumerating endpoint depends on the result of the PE type query. If the detected PE is a switch device, the enumerating endpoint continues to check all of the ports of the newly detected switch to determine whether other PEs are attached to the ports and, if necessary, executes a further PE type query. This querying of individual switches and switch ports is conducted as a branch type operation where the querying of a branch continues until an endpoint PE is detected. Once the detected PE is an endpoint device, the enumerating endpoint assigns a base device ID to the endpoint device and updates the corresponding routing tables in the switch devices of the network. This process may be executed recursively by the enumerating endpoint for each PE located on the RapidIO network until every port of every switch has been queried.
Pseudocode may be used as an example to implement an enumerating process in a RapidIO network, to assign base device IDs to each endpoint, and to configure the routing tables of the switching devices is discussed and illustrated in RapidIO™ Interconnect Specification Annex 1: Software/System Bring Up Specification, Rev. 1.3, February 2005. The processing represented by this pseudocode, however, has several deficiencies. For example, the process does not describe the enumeration of devices appearing on the network after the initial enumeration is completed. Further, the process does not properly configure routing tables for some network topologies. For example, there are certain situations in which the discovery/enumeration sequence of endpoint devices will result in a network configuration in which two or more endpoint devices are unable to communicate. Finally, the process does not assign base device ID values to switch devices, thereby requiring implementation of complicated maintenance and management operations for the switch devices.